An internal combustion engine typically includes a belt assembly driven by a crankshaft of the engine. The belt assembly includes a primary belt (e.g., fan belt, timing belt, accessory belt, etc.) wound about a series of pulleys. As the crankshaft rotates, the primary belt is driven along a path defined by the pulleys. Some of the pulleys are stationary relative to the driven belt, and other pulleys are rotatably driven by the driven belt. One or more of the driven pulleys is coupled to an accessory that utilizes the rotational energy of the driven pulley to provide functionality associated with the accessory. For the belt to remain coupled to the pulleys and to drive the drivable pulleys, the belt must be in tension about the pulleys.
Conventionally, an engine belt is placed in tension about pulleys by operation of a belt tensioner. The belt tensioner includes an arm that is pivotable about a pivot location and a belt pulley secured to an end of the arm. Proximate the pulley is a tool engagement receptacle. The tensioner is rotatable from an unloaded position to a loaded position. With the tensioner in the unloaded position, the belt can be fit loosely about the pulleys of the belt assembly, as well as the pulley of the belt tensioner. With assistance from a tool engaged with the tool engagement receptacle, and the belt held loosely in place, the tensioner can be rotated into the loaded position. As the pulley of the tensioner rotates into the loaded position, the pulley pulls on the belt to place the belt in tension about the pulleys. Although tensioner pivot locations vary by engine model and detail, they are often located near a water pump of the engine proximate a lower left engine quadrant when viewed from the front. Most often, the belt pulley and tool engagement receptacle are located between 10 o'clock and 5 o'clock positions relative to the pivot location and towards the engine crank centerline.
Often, the internal combustion engine includes additional or supplemental accessories that are driven by a secondary belt assembly (e.g., front end accessory drive). The secondary belt assembly includes a secondary belt wound about a set of pulleys in a manner similar to the primary belt assembly. Typically, the secondary belt assembly is positioned longitudinally adjacent or over the primary belt assembly to effectively cover the primary belt assembly. For a fully assembled engine, the position of the secondary belt assembly often significantly limits access to the installation tool engagement receptacle of the tensioner. Accordingly, to remove or install the primary belt, which requires access to the installation tool engagement receptacle of the tensioner, the secondary belt assembly must be removed.
Further, in some engine configurations, the position of the secondary belt assembly does not negatively affect access to the installation tool engagement receptacle, but other components of the engine, or engine congestion in general, may negatively affect such access.